A method of form manufacturing an aircraft engine stator vane

Abstract

The application relates to the technical field of aircraft engine part manufacturing, in particular to a forming manufacturing method of an aircraft engine stator blade, which comprises the following steps: S1, pretreatment, S2, top forging treatment, S3, primary defect treatment, S4, die forging treatment, S5, secondary defect treatment and S6, solid solution aging treatment; after the forming method of top forging+die forging is adopted, the blade has good filling property, the structure is uniform, and the production efficiency is high.

Description

Technical Field

[0001] This invention relates to the field of aircraft engine component manufacturing technology, specifically to a method for forming and manufacturing stator blades for aircraft engines. Background Technology

[0002] Aircraft engines consist of three main components: the compressor, combustion chamber, and turbine, as well as fuel system, lubrication system, air system, electrical system, intake and exhaust side system, and bearing transmission system. Of the three main components, the compressor and turbine (excluding the combustion chamber) are composed of a rotor and a stator. The stator consists of inner and outer casings and guide (rectifying) blades. The rotor consists of blade disks, a shaft, and bearings, with blades being the most numerous. Blades are special parts; they are numerous, complex in shape, demanding in requirements, difficult to manufacture, and prone to failure. They have always been crucial to engine production, thus requiring significant investment of human, material, and financial resources. Furthermore, domestic and international engine manufacturers are actively researching and improving blade performance.

[0003] GH2132 alloy is an age-hardening iron-based austenitic superalloy, similar to the American grade A286. It is suitable for replacing expensive nickel-based alloys in high-temperature environments up to 650°C and is widely used in high-temperature load-bearing components of aero-engines, such as turbine disks, blades, and fasteners. During hot deformation, improper selection of process parameters can lead to inhomogeneous microstructure, stress concentration, and premature fatigue fracture. Simultaneously, the dynamic recrystallization that occurs within the alloy during hot deformation can eliminate defects caused by deformation and reduce the average grain size, which largely determines the final microstructure and mechanical properties of the blade. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a method for forming and manufacturing stator blades for aircraft engines.

[0005] A method for forming and manufacturing a stator blade for an aircraft engine includes the following steps:

[0006] S1, Preheating treatment

[0007] First, the two ends of the bar stock with specifications of Φ50±0.7×430±1mm are measured to the size of 428±1mm, and chamfered to C3~C5. Then, it is machined until the end surface roughness is ≤Ra3.2. Then, it is loaded into the furnace at 1070~1090℃, held for 40~80min, and then taken out of the furnace to obtain the billet.

[0008] S2, Upsetting treatment

[0009] The blank is subjected to three times of top forging treatment at a finish forging temperature of 950-1050℃, and is air cooled to room temperature after each time of top forging treatment, the forging is placed into a die for Step I forming after the first time of air cooling to room temperature, the forging is placed into a die for Step II forming and Step III forming after the second time of air cooling to room temperature, the forging is placed into a die for Step IV forming and Step V forming after the third time of air cooling to room temperature, and a pre-forging is obtained;

[0010] S3, primary defect treatment

[0011] The surface of the pre-forging is cleaned by shot blasting, and then is polished to eliminate defects on the surface of the pre-forging, the surface of the pre-forging is cleaned again by shot blasting, and then the pre-forging is placed into an electric furnace with a furnace temperature of 150-180℃ for heat preservation for 30-40min, and is taken out and sprayed with a glass lubricant;

[0012] S4, die forging treatment

[0013] The forging is subjected to two times of die forging treatment at a finish forging temperature of 950-1050℃, and one time of shot blasting, polishing, two times of shot blasting and lubrication treatment are sequentially performed between the two times of die forging treatment, the impact energy of the two times of die forging treatment is 30±10% and 45±10% of the total impact energy of the equipment respectively, the forging is heated before each time of die forging treatment, the forging is air cooled to room temperature after the first time of die forging treatment, and is hot trimmed after the second time of die forging treatment or is placed on a tray for air cooling and then is cold trimmed, and a target forging is obtained after trimming;

[0014] S5, secondary defect treatment

[0015] The surface of the target forging is cleaned by shot blasting, and then is polished to eliminate defects on the surface of the target forging, and the surface of the target forging is cleaned again by shot blasting;

[0016] S6, solid solution and aging treatment

[0017] The target forging is heated to a temperature of 800-900℃, is kept at 900℃ for 100-120min, is taken out and oil cooled to room temperature, is heated to a temperature of 700-710℃ at room temperature, is kept at 700-710℃ for 950-970min, is taken out and air cooled to a temperature below 40℃, is heated to a temperature of 640-660℃ at room temperature, is kept at 640-660℃ for 950-970min, is taken out and air cooled to a temperature below 40℃, and is subjected to shot blasting to obtain the stator blade of the aircraft engine.

[0018] Further, in step S2, heating treatment is performed before each time of top forging treatment,

[0019] The first time of top forging treatment and the second time of top forging treatment are both as follows: the forging is heated to 1070-1090℃, is kept at 1070-1090℃ for 40-80min, and is taken out;

[0020] The third upsetting treatment method is: heating the forged piece to 1070-1090 °C, holding for 53-106 min, and then taking out the forged piece from the furnace, and when the holding time is 80 min, the forged piece is taken out from the furnace after the holding time ends and is cleaned;

[0021] Description: After the blank is formed by the previous two upsets, the effective thickness is increased. In order to ensure sufficient heat preservation at the forming position and reduce the material deformation resistance to facilitate upset forming, the holding time of the third upset is longer than that of the previous two upsets.

[0022] When the blank exceeds the longest holding time, the blank should be taken out from the heating furnace to prevent further grain growth. After air cooling to room temperature on the tray, the blank is transferred to the shot blasting equipment to remove the surface oxide skin to prevent affecting the subsequent production.

[0023] Further, in step S2, the mold is pretreated, and the pretreatment method is: blowing away the dirt in the mold cavity with compressed air, and spraying graphite inside the mold cavity.

[0024] Description: Blow away the dirt in the mold cavity with compressed air, and evenly blow the graphite with a spray gun to prevent graphite accumulation in the mold cavity and residual graphite in the mold cavity pits.

[0025] Further, the spraying method of the graphite is electrostatic spraying; the electrostatic spray gun of the electrostatic spraying is negative, the metal film forming substrate is positive and grounded, the electrostatic voltage is 1-100 kV, the electrostatic current is 1-100 μA, the output pressure is 0.05-0.1 MPa, the flow rate is controlled at 50-450 mL / min, the spraying distance is 50-350 mm, the spray width is 50-450 mm, and the spraying time is 1-60 s.

[0026] Description: Electrostatic spraying can make graphite more evenly distributed on the workpiece surface, forming a more uniform, smooth and dense coating, and the paint mist splashes less, causing less environmental pollution.

[0027] Further, in step S3, the glass lubricant is GDS-17-1; the spraying method of the glass lubricant is electrostatic spraying; the electrostatic spray gun of the electrostatic spraying is negative, the metal film forming substrate is positive and grounded, the electrostatic voltage is 3-50 kV, the electrostatic current is 20-40 μA, the output pressure is 0.5-0.8 MPa, the flow rate is controlled at 200-300 mL / min, the spraying distance is 150-200 mm, the spray width is 220-300 mm, and the spraying time is 1-5 min.

[0028] Instructions: The lubricant must be thoroughly stirred before use; the operation time from the start to the end of spraying the blank should not exceed 5 minutes, and no areas should be missed. After spraying, avoid impacts to prevent peeling; immediately flip the blank after the first spray and spray the bottom surface. After spraying, allow the glass coating to dry before transferring it to the next process. At high temperatures, the glass lubricant transforms from a solid to a semi-fluid or fluid state, forming a continuous, dense, and ductile pressure-resistant film layer on the contact surface between the blank and the mold, thus providing lubrication. Simultaneously, the molten coating isolates harmful gases in the air throughout the entire hot working process, providing anti-oxidation protection and preventing surface defects caused by oxide scale being carried into the extrusion deformation zone. GDS-17-1 has a low thermal conductivity. When it melts at high temperatures, it surrounds the surface of the billet, forming a dense molten film. The billet and the mold do not directly contact each other, reducing the temperature drop of the billet surface and the temperature rise of the mold, thus providing insulation. This improves the plasticity of the metal and extends the service life of the mold. The conductive underlayer formed by graphite spraying ensures the uniform distribution of the glass lubricant, making the blade surface smooth and uniform without defects. The uniformly distributed glass lubricant effectively reduces the resistance to metal flow and improves the fluidity of the molten metal during high-temperature and high-pressure forging, allowing the molten metal to fill the mold cavity more quickly and completely, thereby obtaining blades with complex shapes.

[0029] Furthermore, in step S4, the heating temperature of the first forging treatment is 1070-1090℃, and the holding time is 75-150 min; the heating temperature of the second forging treatment is 1070-1090℃, and the holding time is 75-150 min.

[0030] Note: The stator blade material in this invention is GH2132 alloy. GH2132 metal has good plasticity in the range of 1070 to 1090°C, making it easy to flow and fill molds with complex shapes, thereby improving the blade's filling performance. By holding the material at 1070 to 1090°C for a certain period of time, it is possible to ensure that the internal structure of the material is fully recrystallized and homogenized, reducing microscopic defects during the forging process and improving the internal quality of the blade.

[0031] Further, in step S4, the parameters for the cold-heated trimming are: heating temperature 850℃±10℃, holding time 15~30min; after trimming, the blade is positioned in the trimming mold, and the dirt on the blade surface is cleaned. Then, the forging misalignment is checked to be ≤1.0mm, and the residual burrs are: residual burrs on one side of the blade body ≤2.0mm, and residual burrs in other positions ≤1.5mm; and any defects are repaired in time to ensure that the forging is defect-free after trimming.

[0032] Description: By heating and holding at a temperature of 850±10℃ for 15-30min, the material can maintain a certain plasticity, which helps to reduce the generation of cracks during trimming, thereby improving the mold filling property of the blade. By controlling the heating temperature and holding time during trimming, the organization of the material can be ensured not to change unevenly during trimming, thereby ensuring the uniformity of the organization of the blade. Compared with cold trimming, cold-state heating trimming can reduce shear stress, thereby reducing the generation of micro-cracks during cold trimming.

[0033] Further, the target forge piece surface after step S5 processing is subjected to weld thinning homogenization treatment, the method of which is: using a small arc-shaped hammer with a radius of 8-10mm to hit the weld of the target forge piece, the hitting force is 2-3N, the hammering rate is 100-140 times / min, the hammering time is 20-30s, so that the metal at the weld of the target forge piece is thinned and elongated to the surrounding, then a layer of heat preservation paint with a thickness of 0.1-0.5μm is sprayed on the thinned weld of the target forge piece, and an alternating current with a frequency of 80-100Hz and a current density of 5-20A / cm 3 is applied for 5-8min.

[0034] Description: Weld thinning homogenization treatment can improve the microstructure of the material by offsetting some weld shrinkage and reducing the weld stress, reducing the thickness of the weld area, thereby improving the mechanical properties of the material. Fine-grained structure is usually accompanied by better strength because grain boundaries can effectively hinder the movement of dislocations. In addition, weld thinning homogenization treatment helps to eliminate or reduce stress concentration generated during welding, which is crucial for improving the fatigue life and crack resistance of the material, indirectly improving the tensile strength of the material. Heat preservation paint can effectively reduce heat loss and improve heating efficiency, which is particularly important for welding and subsequent heat treatment process, because it helps to maintain the appropriate temperature of the weld area, thereby ensuring the welding quality. Secondly, heat preservation paint usually has good thermal shock stability and can resist material expansion and contraction caused by temperature changes, which can reduce the risk of weld damage or cracking caused by temperature fluctuations.

[0035] Further, the heat preservation paint comprises, by mass percentage, 5-10% boron nitride powder, 10-20% talc powder, 10-15% silica aerogel, 3-10% aluminum silicate, 1-3% glass beads, and the balance of water-based epoxy resin.

[0036] Description: The addition of hydrophobic fumed silica can improve the adhesion and tensile strength of the coating, while the pore volume of aerogel helps to reduce the thermal conductivity of the coating, avoiding cracks and peeling, aluminum silicate can improve the thermal conductivity and high temperature resistance of the coating, boron nitride powder has excellent performance of low thermal expansion coefficient, talc has good thermal stability, water-based epoxy resin can promote the bonding force of the thermal insulation coating and the weld thinning area, the spherical structure of glass beads reduces the internal friction resistance of the coating, enhances the flowability of the coating, and makes it easier to penetrate into complex shaped areas, improving the filling effect.

[0037] Further, the spraying method of the thermal insulation coating is supersonic flame thermal spraying, and the process parameters of the supersonic flame thermal spraying are that the distance between the spray gun and the workpiece is 200-220 mm, the spraying angle is 40-60 degrees, and the flow control is 50-450 mL / min.

[0038] Description: The high-speed particle impact generated by supersonic spraying can achieve mechanical interlocking between the coating and the substrate, improving the bonding strength of the coating, which is particularly important for weld thinning areas, as these areas may have stress concentration and require stronger coating adhesion. In the manufacture of high-temperature components such as aircraft engine blades, supersonic flame spraying can significantly improve the wear resistance and corrosion resistance of the material, prolonging the service life of the component.

[0039] Compared with the prior art, the beneficial effects of the present application are:

[0040] (1) After using the top forging + die forging forming method in the present application, the forging temperature and pressure are precisely controlled to ensure smooth flow of the metal in the die, thereby improving the filling property of the blade. Top forging first forms the material preliminarily to provide a suitable blank shape for subsequent die forging, and die forging further refines and perfects the shape of the blade to ensure that the metal can uniformly fill the complex geometry of the die. During die forging, the metal undergoes recrystallization and grain refinement, which helps to obtain a more uniform microstructure. The combination of top forging and die forging can better control the deformation of the material and reduce internal defects such as crack and hole formation, thereby achieving uniformity of the microstructure; the die forging process can more accurately control the use of materials, thereby reducing material waste. Since the forged part is close to the final shape, the loss of material in subsequent processing steps such as cutting and grinding is reduced. The top forging process uses a die, and the deformation of the metal occurs in the die bore, which can quickly obtain the required shape. The blade filling property is improved, the microstructure is uniform, and high automation and continuous production can be achieved, significantly improving production efficiency, suitable for mass production, and high production efficiency.

[0041] (2) The present invention improves the microstructure of the material by reducing the thickness of the weld area through the weld thinning and homogenization treatment, thereby offsetting some weld shrinkage and reducing welding stress. This improves the mechanical properties of the material and helps to eliminate or reduce stress concentration generated during welding, thereby improving the fatigue life and crack resistance of the material and indirectly improving the tensile strength of the material. The thermal insulation coating can effectively reduce heat loss and improve heating efficiency, which is especially important for welding and subsequent heat treatment processes, as it helps to maintain a suitable temperature in the weld area, thereby ensuring welding quality. Attached Figure Description

[0042] Figure 1 This is a three-dimensional schematic diagram of the forging die of the present invention;

[0043] Figure 2 This is a schematic diagram of step I forming of the present invention;

[0044] Figure 3 This is a schematic diagram of step II forming of the present invention;

[0045] Figure 4 This is a schematic diagram of step III forming of the present invention;

[0046] Figure 5 This is a schematic diagram of step IV forming of the present invention;

[0047] Figure 6 This is a schematic diagram of step V forming of the present invention. Detailed Implementation

[0048] To further illustrate the methods and effects of this invention, the technical solution of this invention will be clearly and completely described below in conjunction with experiments.

[0049] Example 1: A method for forming and manufacturing a stator blade for an aircraft engine, comprising the following steps:

[0050] S1, Preprocessing

[0051] First, the two ends of the bar stock with a specification of Φ50×430mm are measured to a size of 428mm, and chamfered to C4. The end face is machined to a roughness of Ra3.2. Then, it is loaded into the furnace at 1080℃, held for 60 minutes, and then taken out of the furnace to obtain the billet.

[0052] S2, Upsetting treatment

[0053] The blank is subjected to three times of top forging treatment under the condition of a final forging temperature of 1000 DEG C, and is air-cooled to 27 DEG C after each top forging treatment, the first time of air-cooling to room temperature, the forging piece is placed into a die for I-step forming, the second time of air-cooling to room temperature, the forging piece is placed into a die for II-step forming and III-step forming, the third time of air-cooling to room temperature, the forging piece is placed into a die for IV-step forming and V-step forming, and a pre-forging piece is obtained; wherein, the I-step forming corresponds to the first time of top forging treatment, the II-step and III-step forming correspond to the second time of top forging treatment, and the IV-step and V-step forming correspond to the third time of top forging treatment; Figure 1 The molds corresponding to the I-step forming, the II-step and III-step forming, the IV-step forming and the V-step forming are sequentially arranged from top to bottom;

[0054] S3, primary defect treatment

[0055] The surface of the pre-forging piece is removed by shot blasting at a speed of 75 m / s for 15 min, and then polished to eliminate defects on the surface of the pre-forging piece, and the surface of the pre-forging piece is cleaned by shot blasting again at a speed of 75 m / s for 35 min, and then the pre-forging piece is placed in an electric furnace with a furnace temperature of 160 DEG C for 35 min, and then sprayed with a glass lubricant; wherein, the polishing defect shall not exceed 2 / 3 of the machining allowance, and the polishing width is 6 times the polishing depth;

[0056] S4, die forging treatment

[0057] The forging piece is subjected to 2-fire die forging treatment under the condition of a final forging temperature of 1000 DEG C, and one shot blasting, polishing and two shot blastings and spraying of a glass lubricant are sequentially performed between the 2-fire die forging treatments at a speed of 75 m / s for 15 min and at a speed of 75 m / s for 35 min, respectively, and then the pre-forging piece is placed into a die cavity for die forging, and the striking energy of the 2-fire die forging treatment is 30% and 45% of the total striking energy of the equipment, respectively; each fire die forging treatment is preceded by a heating treatment, the first fire die forging treatment is air-cooled to 27 DEG C, and the second fire die forging treatment is trimmed while hot, and then air-cooled to obtain a target forging piece; wherein, the polishing defect shall not exceed 2 / 3 of the machining allowance, and the polishing width is 6 times the polishing depth;

[0058] S5, secondary defect treatment

[0059] The surface of the target forging piece is removed by shot blasting at a speed of 75 m / s for 15 min, and then polished to eliminate defects on the surface of the target forging piece, and the surface of the target forging piece is cleaned by shot blasting again at a speed of 75 m / s for 35 min, wherein, the polishing defect shall not exceed 2 / 3 of the machining allowance, and the polishing width is 6 times the polishing depth;

[0060] S6, solid solution and aging treatment

[0061] The temperature is 850℃ when charging into the furnace, then the temperature is kept at 900℃ for 110min, the furnace is discharged and oil-cooled to 27℃, then the temperature is kept at 27℃ when charging into the furnace again, and the temperature is kept at 705℃ for 960min, the furnace is discharged and air-cooled to below 40℃, the temperature is kept at 27℃ when charging into the furnace again, and the temperature is kept at 650℃ for 960min, the furnace is discharged and air-cooled to 40℃, and the airplane engine stator blade is obtained after the shot blasting treatment;

[0062] In step S2, the heating treatment is carried out before each upsetting treatment, and the method of the first upsetting treatment and the second upsetting treatment is as follows: the forged piece is heated to 1080℃, and the temperature is kept for 60min before discharging the furnace;

[0063] The method of the third upsetting treatment is as follows: the forged piece is heated to 1080℃, and the temperature is kept for 75min before discharging the furnace, and the fishing cleaning is carried out after the end of the temperature keeping time;

[0064] In step S2, the mold is pretreated, and the method of the pretreatment is as follows: the dirt in the mold cavity is blown clean by compressed air, and the graphite is sprayed in the mold cavity; the spraying method of the graphite is electrostatic spraying, in which the electrostatic spraying gun is negative, the metal film forming matrix at the weld is positive and grounded, the electrostatic voltage is 50kV, the electrostatic current is 50μA, the output pressure is 0.08MPa, the flow rate is controlled at 280mL / min, the spraying distance is 200mm, the spray width is 250mm, and the spraying time is 30s;

[0065] In step S3, the glass lubricant is GDS-17-1; the spraying method of the glass lubricant is electrostatic spraying; the electrostatic spraying gun is negative, the metal film forming matrix is positive and grounded, the electrostatic voltage is 25kV, the electrostatic current is 30μA, the output pressure is 0.65MPa, the flow rate is controlled at 250mL / min, the spraying distance is 175mm, the spray width is 270mm, and the spraying time is 3min;

[0066] In step S4, the heating temperature of the first die forging treatment is 1080℃, and the temperature keeping time is 100min; the heating temperature of the second die forging treatment is 1080℃, and the temperature keeping time is 120min;

[0067] In step S4, the parameters of the cold-state heating trimming are as follows: the heating temperature is 850℃, and the temperature keeping time is 22min; after the trimming treatment, the blade is positioned in the trimming die, the surface dirt of the blade is cleaned, then the upsetting of the forged piece is checked to be 1.0mm, the residual burr of the blade body single side is 2.0mm, the residual burr of the other positions is 1.5mm, the existing defects are repaired in time, and the forged piece after the trimming is ensured to be defect-free.

[0068] It should be noted that the processes such as polishing, shot blasting, and lubricating involved in the embodiments of the present application are all conventional processes, and the specific contents are not limited in the present case and will not be described herein.

[0069] Example 2: Different from example 1, in step S1, the bar material with a specification of Φ49.3*429mm is first trimmed to a size of 427mm at both ends and chamfered to C3, and the end face is turned to a roughness of Ra3.2, and then the bar material is loaded into the furnace at 1070℃, and after holding for 40min, the bar material is taken out of the furnace to obtain the blank.

[0070] Example 3: Different from example 1, in step S1, the bar material with a specification of Φ50.7*431mm is first trimmed to a size of 429mm at both ends and chamfered to C5, and the end face is turned to a roughness of Ra3.2, and then the bar material is loaded into the furnace at 1090℃, and after holding for 80min, the bar material is taken out of the furnace to obtain the blank.

[0071] Example 4: Different from example 1, in step S2, the mold is pretreated, and the pretreatment method is: blowing away the dirt in the mold cavity with compressed air, and spraying graphite inside the mold cavity.

[0072] Example 5: Different from example 1, in step S2, the mold is pretreated, and the pretreatment method is: blowing away the dirt in the mold cavity with compressed air, and spraying graphite inside the mold cavity.

[0073] Example 6: Different from example 1, in step S3, the dirt on the surface of the preform is removed by shot blasting at a shot blasting speed of 50m / s and a shot blasting time of 10min, and then polishing is performed to eliminate the defects on the surface of the preform, and then the surface of the preform is cleaned by shot blasting at a shot blasting speed of 50m / s and a shot blasting time of 30min, and then the preform is placed in an electric furnace with a furnace temperature of 150℃ for 30min, and after taking out, a glass lubricant is sprayed; wherein the polishing defects should not exceed 2 / 3 of the machining allowance, and the polishing width is 6 times the polishing depth.

[0074] Example 7: Different from example 1, in step S3, the dirt on the surface of the preform is removed by shot blasting at a shot blasting speed of 100m / s and a shot blasting time of 20min, and then polishing is performed to eliminate the defects on the surface of the preform, and then the surface of the preform is cleaned by shot blasting at a shot blasting speed of 100m / s and a shot blasting time of 40min, and then the preform is placed in an electric furnace with a furnace temperature of 180℃ for 40min, and after taking out, a glass lubricant is sprayed; wherein the polishing defects should not exceed 2 / 3 of the machining allowance, and the polishing width is 6 times the polishing depth.

[0075] Example 8: Different from example 1, the electrostatic spraying parameters of graphite are: electrostatic high voltage is 1 kV, electrostatic current is 1 μA, output pressure is 0.05 MPa, flow control is 50 mL / min, spraying distance is 50 mm, spray width is 50 mm, and spraying time is 1 s.

[0076] Example 9: Different from example 1, the electrostatic spraying parameters of graphite are: electrostatic high voltage is 100 kV, electrostatic current is 100 μA, output pressure is 0.1 MPa, flow control is 450 mL / min, spraying distance is 350 mm, spray width is 450 mm, and spraying time is 60 s.

[0077] Example 10: Different from example 1, in step S4, the pre-forging is subjected to 2-time die forging treatment at a final forging temperature of 950 ℃, and between the 2-time die forging treatment, the pre-forging is subjected to one-time shot blasting at a shot blasting speed of 50 m / s and a shot blasting time of 10 min, polishing, two-time shot blasting at a shot blasting speed of 50 m / s and a shot blasting time of 30 min, and spraying of glass lubricant, and then the pre-forging is placed into a die cavity for die forging, the impact energy of the 2-time die forging treatment is 20% and 35% of the total impact energy of the equipment respectively, the polishing defect is 2 / 3 of the machining allowance, and the polishing width is 6 times the polishing depth.

[0078] In the electrostatic spraying process of the glass lubricant, the electrostatic voltage is 3 kV, the electrostatic current is 20 μA, the output pressure is 0.5 MPa, the flow control is 200 mL / min, the spraying distance is 150 mm, the spray width is 220 mm, and the spraying time is 1 min.

[0079] Example 11: Different from example 1, in step S4, the pre-forging is subjected to 2-time die forging treatment at a final forging temperature of 1000 ℃, and between the 2-time die forging treatment, the pre-forging is subjected to one-time shot blasting at a shot blasting speed of 100 m / s and a shot blasting time of 20 min, polishing, two-time shot blasting at a shot blasting speed of 100 m / s and a shot blasting time of 340 min, and spraying of glass lubricant with a thickness of 200 μm, and then the pre-forging is placed into a die cavity for die forging, the impact energy of the 2-time die forging treatment is 40% and 55% of the total impact energy of the equipment respectively, the polishing defect is 2 / 3 of the machining allowance, and the polishing width is 6 times the polishing depth.

[0080] In the electrostatic spraying process of the glass lubricant, the electrostatic voltage is 50 kV, the electrostatic current is 40 μA, the output pressure is 0.8 MPa, the flow control is 300 mL / min, the spraying distance is 200 mm, the spray width is 300 mm, and the spraying time is 5 min.

[0081] Example 12: Different from example 1, in step S4, the heating temperature of the first-time die forging treatment is 1070℃, and the holding time is 75min; the heating temperature of the second-time die forging treatment is 1070℃, and the holding time is 75min.

[0082] Example 13: Different from example 1, in step S4, the heating temperature of the first-time die forging treatment is 1090℃, and the holding time is 150min; the heating temperature of the second-time die forging treatment is 1090℃, and the holding time is 150min.

[0083] Example 14: Different from example 1, in step S4, the parameters of the cold heating trimming are as follows: the heating temperature is 860℃, and the holding time is 30min.

[0084] Example 15: Different from example 1, in step S5, the dirt on the surface of the target forging is removed by shot blasting at a speed of 50m / s for 30min, and then the defects on the surface of the target forging are eliminated by polishing, and the surface of the target forging is cleaned by shot blasting at a speed of 50m / s for 30min again, the polishing defects should not exceed 2 / 3 of the machining allowance, and the polishing width is 6 times of the polishing depth.

[0085] Example 16: Different from example 1, in step S5, the dirt on the surface of the target forging is removed by shot blasting at a speed of 100m / s for 40min, and then the defects on the surface of the target forging are eliminated by polishing, and the surface of the target forging is cleaned by shot blasting at a speed of 100m / s for 40min again, the polishing defects should not exceed 2 / 3 of the machining allowance, and the polishing width is 6 times of the polishing depth.

[0086] Example 17: Different from example 1, in step S6, the target forging is loaded into the furnace at a temperature of 800℃, and then held at 900℃ for 100min, and then oil-cooled to 22℃, and then loaded into the furnace at 22℃, and held at 700℃ for 950min, and then air-cooled to below 40℃ after being discharged from the furnace, and then loaded into the furnace at 22℃ again, and held at 640℃ for 950min, and then air-cooled to below 40℃ after being discharged from the furnace, and then the aircraft engine stator blade is obtained after shot blasting treatment.

[0087] Example 18: Different from example 1, in step S6, the target forging is loaded into the furnace at a temperature of 900℃, and then held at 900℃ for 120min, and then oil-cooled to 30℃, and then loaded into the furnace at 30℃, and held at 710℃ for 970min, and then air-cooled to below 40℃ after being discharged from the furnace, and then loaded into the furnace at 30℃ again, and held at 660℃ for 970min, and then air-cooled to below 40℃ after being discharged from the furnace, and then the aircraft engine stator blade is obtained after shot blasting treatment.

[0088] Example 19: Different from example 1, the target forge piece surface after the step S5 treatment is completed is subjected to a weld thinning homogenization treatment, and the method of the weld thinning homogenization treatment is as follows: a small hammer with a radius of about 9mm in arc shape is used to hit the weld of the target forge piece, the hitting force is 2.5N, the hammering rate is 120 times / min, the hammering time is 25s, the metal at the weld of the target forge piece is thinned and elongated to the surrounding, then a layer of heat preservation paint with a thickness of 2μm is sprayed on the thinned weld of the target forge piece, and an alternating current with a frequency of 90Hz and a current density of 12A / cm 3 is applied for 6min;

[0089] The heat preservation paint includes 8% boron nitride powder, 15% talc powder, 13% silica aerogel, 7% aluminum silicate, 2% glass beads and the balance of water-based epoxy resin in percentage by mass;

[0090] The spraying method is supersonic flame thermal spraying; the distance between the spray gun and the workpiece is adjusted to 210mm, the spraying angle is 50°, and the flow is controlled at 250mL / min during supersonic flame thermal spraying.

[0091] Example 20: Different from example 19, a small hammer with a radius of about 8mm in arc shape is used to hit the weld of the target forge piece, the hitting force is 2N, the hammering rate is 100 times / min, the hammering time is 20s, the metal at the weld of the target forge piece is thinned and elongated to the surrounding, then a layer of heat preservation paint with a thickness of 1μm is sprayed on the thinned weld of the target forge piece, and an alternating current with a frequency of 80Hz and a current density of 5A / cm 3 is applied for 5min.

[0092] Example 21: Different from example 19, a small hammer with a radius of about 10mm in arc shape is used to hit the weld of the target forge piece, the hitting force is 3N, the hammering rate is 140 times / min, the hammering time is 30s, the metal at the weld of the target forge piece is thinned and elongated to the surrounding, then a layer of heat preservation paint with a thickness of 3μm is sprayed on the thinned weld of the target forge piece, and an alternating current with a frequency of 100Hz and a current density of 20A / cm 3 is applied for 8min.

[0093] Example 22: Different from example 19, the heat preservation paint includes 5% boron nitride powder, 10% talc powder, 10% silica aerogel, 3% aluminum silicate, 1% glass beads and the balance of water-based epoxy resin in percentage by mass.

[0094] Example 23: Different from example 19, the heat preservation coating comprises 10% boron nitride powder, 20% talc powder, 15% silica aerogel, 10% aluminum silicate, 3% glass microbeads, and the balance of water-based epoxy resin by mass percentage.

[0095] Example 24: Different from example 19, the process parameters of the high-velocity oxygen fuel thermal spraying are that the distance between the spray gun and the workpiece is 200 mm, the spraying angle is 40°, and the flow rate is controlled at 50 mL / min.

[0096] Example 25: Different from example 19, the process parameters of the high-velocity oxygen fuel thermal spraying are that the distance between the spray gun and the workpiece is 220 mm, the spraying angle is 60°, and the flow rate is controlled at 450 mL / min.

[0097] Experimental example: The description basis of the experimental example is the recorded scheme in examples 1-25, which aims to illustrate the actual application effect of the present application. The appearance and mechanical properties of the aviation blades obtained in examples 1-25 are tested, and comparative examples are set.

[0098] The blade forgings produced by the methods of examples 1-25 are subjected to 100% visual inspection, and the blade forgings of examples 1-25 are all good in surface quality and free of cracks, folds and other defects; the tensile strength and crack resistance of the blades of examples 19-25 are better, and the quality is higher than that of examples 1-18; comparative examples 1-5 have slight cracks on the surface, and the surface quality is not as good as that of examples 1-25; it is illustrated that the method of examples 1-25 is better; the metallographic structure of the aviation blades obtained in examples 1-25 is observed, and the grain size is 10 or less, and the distribution is uniform;

[0099] 1. Explore the influence of forming manufacturing parameters on the mechanical properties of the blades;

[0100] Table 1 Mechanical properties of stator blade of examples 1-18 and comparative examples 1-4

[0101]

[0102]

[0103] Comparative example 1: Different from example 1, in step S2, the heat preservation time of the third upset is consistent with the first and second times.

[0104] Comparative example 2: Different from example 1, in step S2, the mold is not pretreated.

[0105] Comparative Example 3: Different from Example 1, in step S3, the glass lubricant is a new type of glass lubricant (such as B2O3-SiO2-Al2O3-Na2O-TiO2system).

[0106] Comparative Example 4: Different from Example 1, in step S4, the trimming method is cold trimming.

[0107] From the data in Table 1, it can be seen that, by comparing the data of Example 1, Example 2, Example 3 and Comparative Example 2, the mechanical properties of the stator blade in Comparative Example 2 are decreased due to the fact that the holding time is not adjusted. The main reason is that the effective thickness of the blank increases after the first two upset forming, in order to ensure sufficient holding of the forming position, reduce the material deformation resistance, and thus improve the efficiency of the upset forming and the mechanical properties of the forged piece, the holding time of the third upset forming needs to be longer than the first two times;

[0108] By comparing the data of Example 1, Example 4, Example 5 and Comparative Example 2, it can be seen that the mechanical properties of the forged piece are also decreased without the pre-treatment of the mold. Graphite is a common material that is often sprayed inside the mold cavity. Its main functions include lubrication, heat conduction, and anti-sticking. Graphite has natural lubricating properties, and its crystal structure allows relative sliding between layers. Spraying graphite inside the mold cavity can significantly reduce the friction between the mold and the molten metal, thereby improving the filling effect. Graphite also has excellent thermal conductivity, which is much higher than most metal materials, which means that the graphite layer can quickly conduct heat away, thereby accelerating the solidification process of the molten metal, which is crucial for the filling effect. Because during the filling stage, the rapid solidification of the liquid material can help maintain its shape accuracy, further improve the filling effect of the blade and thus improve the mechanical properties.

[0109] From the comparison of Example 1, Example 10, Example 11 and Comparative Example 3, it can be seen that the glass lubricant is further optimized in viscosity and structural stability at high temperature by introducing titanium oxide into the new glass lubricant. The presence of titanium oxide not only strengthens the network structure and reduces the viscosity, but also maintains a longer flow time at extremely high temperature, and to some extent, improves the mechanical properties of the stator blade. However, compared with GDS-17-1, the effect is slightly weaker, because at high temperature, the lubricating effect of GDS-17-1 at high temperature can effectively control the microstructure of the metal blade, reduce surface defects and subsurface damage caused by friction. These changes in microstructure directly affect the mechanical properties of the material, such as strength, toughness and fatigue life. In the process of high-temperature forging, the protective film formed by GDS-17-1 can prevent the oxidation of the metal surface, thereby maintaining the metal density and improving the mechanical properties. Oxidation porosity can cause cavities and cracks in the material, which seriously affect its mechanical properties. The effective protection of GDS-17-1 avoids these problems. By reducing the friction between the mold and the workpiece, GDS-17-1 makes the stress more evenly distributed on the metal blade, avoiding defects caused by local stress concentration. This not only improves the overall mechanical properties of the blade, but also prolongs its service life. Compared with other common glass lubricants, GDS-17-1 performs well in composition diversity, particle size control and environmental friendliness, and can adapt to a variety of complex high-temperature processing environments.

[0110] From the comparison of Example 1, Example 14 and Comparative Example 4, it can be seen that the hot slicing and cold cutting of the stator blade have little effect on the mechanical properties of the stator blade, while the cold cutting of Comparative Example 4 causes a significant decrease in the mechanical properties of the stator blade. This is because cold cutting under heat can reduce shear stress and reduce the generation of micro-cracks during cold cutting, thereby further improving the mechanical properties. Considering the overall cost, Example 1 is the optimal solution.

[0111] 2. Explore the effect of weld thinning homogenization treatment on the mechanical properties of the stator blade

[0112] Table 2 Mechanical properties of stator blades of Example 1, Examples 19-25, Comparative Examples 5-7

[0113]

[0114]

[0115] Comparative Example 5: Unlike Example 19, no alternating current is applied to the surface of the heat preservation coating.

[0116] Comparative Example 6: Unlike Example 19, no glass beads are added to the heat preservation coating.

[0117] Comparative Example 7: Unlike Example 19, the spraying method of the heat preservation coating was electrostatic spraying.

[0118] Conclusion: From the comparison of Example 1, Example 19 to Example 25, it can be seen that the stator blade after the weld thinning homogenization treatment has obvious improvement in various performances compared with Example 1, and the best performance can be achieved under the parameters of Example 19; this is because the weld thinning homogenization treatment can offset some weld shrinkage, reduce weld stress, and reduce the thickness of the weld area to improve the microstructure of the material, thereby improving the mechanical properties of the material; from the comparison of Example 19 to Example 21 and Comparative Example 5, it can be seen that the performance of the stator blade will decrease without applying alternating current during the spraying process of the heat preservation coating, mainly because the alternating current can generate a changing magnetic field in the metal liquid, and this magnetic field can generate a Lorentz force on the conductive metal liquid, causing the metal liquid to flow, which can significantly enhance the flowability of the metal liquid, making it easier to fill the mold cavity with complex shape, especially in the weak part of the weld thinning, electromagnetic stirring can effectively prevent the occurrence of shrinkage porosity at the hot spot, and the electromagnetic field generated by the alternating current can refine the crystalline structure of the metal liquid, making the crystal grains smaller and more uniform, and the principle of fine-grain strengthening is that there are more small grain boundaries, which can better hinder the movement of dislocations, thereby improving the strength and hardness of the stator blade; in addition to electromagnetic stirring, the alternating current can also generate heat through electromagnetic induction, which can compensate for the temperature drop of the metal liquid during solidification, further reducing the probability of casting defects such as cold shut and shrinkage porosity; from the comparison of Example 19, Example 22, Example 23 and Comparative Example 6, it can be seen that the performance of the blade without adding glass beads in the heat preservation coating also decreases, spherical glass beads have good flowability, which can effectively reduce the viscosity and internal stress of the coating, thereby improving the overall construction performance and reducing coating defects, and further improving the performance of the stator blade, the lack of glass beads will increase the viscosity of the coating and reduce the flowability, making it difficult to penetrate into complex geometric parts, which may cause insufficient filling, affecting the forming quality and detail integrity of the blade; from the comparison of Example 19, Example 24, Example 25 and Comparative Example 7, it can be seen that compared with the ultrasonic flame thermal coating, the coating formed by electrostatic spraying is relatively loose, and the heat preservation effect of the loose coating is poor during the filling process of the blade, and the heat is more easily lost, which may cause the temperature of the metal liquid inside the blade to be uneven, thereby affecting the filling effect and causing defects such as cold shut and insufficient pouring, thereby weakening the mechanical properties. In summary, Example 19 provides a method for preparing an engine stator blade with good mechanical properties and filling properties.

Claims

1. A method of form manufacturing of an aircraft engine stator vane, characterized by, It comprises the following steps: S1, pretreatment Firstly, the bar material with a specification of Φ50±0.7*430±1mm is deburred to a size of 428±1mm and chamfered to C3~C5, and then turned to an end surface roughness of ≤Ra3.2, and then put into a furnace at 1070~1090℃, and after heat preservation treatment for 40~80min, taken out of the furnace to obtain a blank; S2, top forging treatment Under the condition of a final forging temperature of 950~1050℃, the blank is subjected to three times of top forging treatment, and after each top forging treatment, air cooling is performed to room temperature, and after the first time of air cooling to room temperature, the forged piece is put into a die for I-step forming, and after the second time of air cooling to room temperature, the forged piece is put into a die for II-step forming and III-step forming, and after the third time of air cooling to room temperature, the forged piece is put into a die for IV-step forming and V-step forming to obtain a pre-forged piece; S3, primary defect treatment The pre-forged piece is subjected to shot blasting to remove dirt on the surface of the pre-forged piece, and then polished to eliminate defects on the surface of the pre-forged piece, and then subjected to shot blasting again to clean the surface of the pre-forged piece, and then placed in an electric furnace with a furnace temperature of 150~180℃ for heat preservation for 30~40min, and after taken out, sprayed with a glass lubricant; S4, die forging treatment The forged piece is subjected to 2-fire times of die forging treatment under the condition of a final forging temperature of 950~1050℃, and between the 2-fire times of die forging treatment, in sequence, one time of shot blasting, polishing, two times of shot blasting and lubrication treatment are performed, and the impact energy of the 2-fire times of die forging treatment is 30±10% and 45±10% of the total impact energy of the equipment respectively; before each fire time of die forging treatment, heating treatment is performed, after the first fire time of die forging treatment, air cooling is performed to room temperature, and after the second fire time of die forging treatment, hot trimming is performed or first placed on a tray for air cooling and then cold-state heating trimming is performed, and after trimming, air cooling is performed to obtain a target forged piece; S5, secondary defect treatment The target forge piece is cleaned by shot blasting, then polished to eliminate defects on the surface of the target forge piece, and the surface of the target forge piece is cleaned again by shot blasting; the surface of the target forge piece after the treatment in S5 is subjected to weld thinning homogenization treatment, and the method of the weld thinning homogenization treatment is as follows: a small arc-shaped hammer with a radius of about 8-10 mm is used to strike the weld of the target forge piece, the striking force is 2-3 N, the hammering rate is 100-140 times / min, the hammering time is 20-30 s, the metal at the weld of the target forge piece is thinned and elongated to the surrounding, then a layer of heat preservation paint with a thickness of 0.1-0.5 μm is sprayed on the thinned weld of the target forge piece, and an alternating current with a frequency of 80-100 Hz and a current density of 5-20 A / cm 3 is applied to the thinned weld of the target forge piece for 5-8 min; the heat preservation paint contains, in percentage by mass, 5-10% of boron nitride powder, 10-20% of talc powder, 10-15% of silica aerogel, 3-10% of aluminum silicate, 1-3% of glass beads, and the balance of water-based epoxy resin. S6, solid solution and aging treatment Put into a furnace at a temperature of 800~900℃, then heat preservation at 900℃ for 100~120min, taken out of the furnace and oil cooled to room temperature, then put into a furnace at room temperature and heat preservation at 700~710℃ for 950~970min, taken out of the furnace and air cooled to below 40℃, put into a furnace at room temperature again and heat preservation at 640~660℃ for 950~970min, taken out of the furnace and air cooled to below 40℃, and after shot blasting treatment, an aircraft engine stator blade is obtained.

2. A method of form fabrication of an aircraft engine stator vane as defined in claim 1 wherein, In step S2, heating treatment is performed before each time of top forging treatment, The method of the first and second times of top forging treatment is: heating the forged piece to 1070~1090℃, heat preservation treatment for 40~80min and taken out of the furnace; The method of the third time of top forging treatment is: heating the forged piece to 1070~1090℃, heat preservation treatment for 53~106min and taken out of the furnace, and when the heat preservation treatment time is 80min, after the heat preservation treatment time ends, respectively, perform fishing cleaning.

3. A method of form fabrication of an aircraft engine stator vane as defined in claim 1 wherein, In step S2, the die is subjected to pretreatment, and the method of the pretreatment is: blowing dirt in the die cavity with compressed air, and spraying graphite in the die cavity.

4. A method of form fabrication of an aircraft engine stator vane as defined in claim 3 wherein, The spraying method of the graphite is electrostatic spraying; the electrostatic spraying gun is negative, the metal film forming matrix is positive and grounded, the electrostatic voltage is 1-100 kV, the electrostatic current is 1-100 μA, the output pressure is 0.05-0.1 MPa, the flow rate is controlled to be 50-450 mL / min, the spraying distance is 50-350 mm, the spray width is 50-450 mm, and the spraying time is 1-60 s.

5. A method of form fabrication of an aircraft engine stator vane as defined in claim 1 wherein, In step S3, the glass lubricant is GDS-17-1; the spraying method of the glass lubricant is electrostatic spraying; the electrostatic spraying gun is negative, the metal film forming matrix is positive and grounded, the electrostatic voltage is 3-50 kV, the electrostatic current is 20-40 μA, the output pressure is 0.5-0.8 MPa, the flow rate is controlled to be 200-300 mL / min, the spraying distance is 150-200 mm, the spray width is 220-300 mm, and the spraying time is 1-5 min.

6. A method of form fabrication of an aircraft engine stator vane as defined in claim 1 wherein, In step S4, the heating temperature of the first-time die forging treatment is 1070-1090 °C, and the holding time is 75-150 min; the heating temperature of the second-time die forging treatment is 1070-1090 °C, and the holding time is 75-150 min.

7. A method of form fabrication of an aircraft engine stator vane as defined in claim 1 wherein, In step S4, the parameters of the cold-state heating trimming are as follows: the heating temperature is 850 °C±10 °C, and the holding time is 15-30 min; after the trimming treatment, the blade is positioned in the trimming die, the surface dirt of the blade is cleaned, then the forging part is checked, the displacement is ≤1.0 mm, the residual burr is ≤2.0 mm on the single side of the blade body, and the residual burr is ≤1.5 mm at other positions, and the existing defects are repaired in time to ensure that the forging part after trimming is defect-free.

8. A method of form fabrication of an aircraft engine stator vane as defined in claim 1 wherein, The spraying method of the heat preservation coating is supersonic flame thermal spraying; the process parameters of the supersonic flame thermal spraying are as follows: the distance between the spraying gun and the workpiece is 200-220 mm, the spraying angle is 40-60°, and the flow rate is controlled to be 50-450 mL / min.

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